Given its history as a pretty middling Pokémon with little value outside the story of the Pokémon world, it's a little weird that one of the rarer and more sought-after Pokémon in Pokémon Go is the humble Unown. Some fans think that Niantic is holding it in reserve for a special legendary event, but the fact of the matter remains that Unown does spawn, just very rarely.

Unown spawns so rarely in fact, that a poster on the Silph Road was able to map out its reported spawns for the greater London area just to see how rare it was.

In a post on the Silph Road, user Topottsel catalogued the reported Unown spawns in London from a tracker feed they'd found on Twitter. They did this in order to see if there was any kind of rhyme or reason to where and when Unown was more likely to spawn, and they used the data to create a map of where these spawns took place, using the latitude and longitude of the reported Unown spawns.

Topottsel's Unown "heat map," showing where spawns have been reported in the city. Topottsel/Imgur

While collecting the data for the map, Topottsel uncovered several pieces of evidence. Since the launch of Gen 2, the tracker they'd used had only reported 148 Unown spawns in the area surveyed, and no "blob" on their heat map indicated a spawn of any more than two or three Unown. There are anywhere from zero to five Unown spawns per day, with an average of about two. Topottsel used this evidence to conclude that there wasn't really any rhyme or reason as to when Unown spawns, and your best bet would simply be to hang around the parks in Central London where spawns are more clustered in general.

Another poster used this data to extrapolate exactly how rare it was to come across an Unown in a major metropolitan area, and the results were, uh, not good. An area the size of Topottsel's map would have about 10 million spawns that reset every hour, for a total of 240 million over the course of a 24-hour period. Assuming a spawn rate of two per day for Unown, that means the average person has a one-in-120 million chance of finding one, or 0.00000000083%.

While Topottsel was very clear to state that their data was in no way large enough to draw any larger conclusions from, the fact that there have only been 148 reported Unown spawns since Gen 2 dropped should probably still give us pause. With a spawn rate that low, it's not unusual to suppose that Niantic has something special in store for the Unown, even if we don't know what that is.